Error reconfiguring bind on server: rndc: connection to remote host closed
This may indicate that the remote server is using an older version of
the command protocol, this host is not authorized to connect,
or the key is invalid.

I had the same problem.
To fix this do the following:
cd /etc
mv rndc.conf _rndc.conf
/scripts/fixrndc

It seems that the source of the problem is the /etc/rndc.conf

To test that the problem has been fixed, run /scripts/upcp(this is the script that runs every day and by calling the /scripts/fixrndc, creates a corrupt /etc/rndc.key) and then check if named is still running and /etc/rndc.key secret is valid.